Update Aug. 24: The Warren forum was cancelled. Rick Warren says it's because the campaign is toxic. The campaigns say it was because they didn't think it was in their best interest. Warren, after all, has publicly differentiated between Mormons and Christians, so it wasn't in Romney's best interest.
Via Election Central:
October 3, 2012 Air Time TBD
Location: University of Denver in Denver, Colorado
Sponsor: Commission on Presidential Debates
Participants: President Barack Obama and Mitt Romney
October 11, 2012
Vice Presidential Air Time TBD
Location: Centre College in Danville, Kentucky
Sponsor: Commission on Presidential Debates
Participants: Vice President Biden and the GOP Vice Presidential nominee
October 16, 2012 Air Time TBD
Location: Hofstra University in Hempstead, New York
Sponsor: Commission on Presidential Debates
Participants: President Barack Obama and Mitt Romney
October 22, 2012 Air Time TBD
Location: Lynn University in Boca Raton, Florida
Sponsor: Commission on Presidential Debates
Participants: President Barack Obama and Mitt Romney
Other planned debates include a forum at Saddleback Church with pastor Rick Warren as moderator. No date has been announced yet.
Slate has a roundup of the debate formats, which includes a town hall style.